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Forest volume growth between two measurements is often decomposed into the components of survivor growth (S), ingrowth(Z), mortality (M), and cut (C) (for example, Beers 1962 or Van Deusen et al. 1986). Net change between volumes at times 1 and 2 (V1 - V2) is then represented by the equation V,-V,=S+I-M-C. Two new compatible pairs of estimators for S and Z in this...

Two estimators for volume at time 1 for use with permanent horizontal point samples are evaluated. One estimator, used traditionally, uses only the trees sampled at time 1, while the second estimator, originally presented by Roesch and coauthors (F.A. Roesch, Jr., E.J. Green, and C.T. Scott. 1989. For. Sci. 35(2):281-293). takes advantage of additional sample...

Compatible groups of estimators for total value at time 1 (V1), survivor growth (S), and ingrowth (I) for use with permanent horizontal point samples are evaluated for the special cases of estimating the change in both the number of trees and basal area. Caveats which should be observed before any one compatible grouping of estimators is chosen...

Forest survey analysts usually are interested in tables of values rather than single point estimates. A common error is to include only plots on which nonzero values of the attribute were observed when computing the variance of a mean. Similarly, analysts often exclude nonforest plots from the analysis. The development of the correct estimates of forest area, attribute...

Uncertainties are a composite of errors arising from observations and the appropriateness of models. An error budget approach can be used to identify and accumulate the sources of errors to estimate change in emissions between two points in time. Various forest monitoring approaches can be used to estimate the changes in emissions due to deforestation and forest...

Engineers and hydrologists use the curve number method to estimate runoff from rainfall for different land use and soil conditions; however, large uncertainties occur for estimates from forested watersheds. This investigation evaluates the accuracy and consistency of the method using rainfall-runoff series from 10 small forested-mountainous watersheds in the eastern...

An analysis of trees in Toronto, Ontario, reveals that this city has about 10.2 million trees with a tree and shrub canopy that covers approximately 26.6 percent of the city. The most common tree species are eastern white-cedar, sugar maple, and Norway maple. The urban forest currently stores an estimated 1.1 million metric tons of carbon valued at CAD$25.0 million. In...

Many engineers and hydrologists use the curve number method to estimate runoff from ungaged watersheds; however, the method does not explicitly account for the influence of season or forest cutting on runoff. This study of observed rainfall and runoff for small, forested watersheds that span the Appalachian Mountains of the eastern United States showed that curve...

Adequately predicting the sampling errors of tabular data can reduce printing costs by eliminating the need to publish separate sampling error tables. Two generalized variance functions (GVFs) found in the literature and three GVFs derived for this study were evaluated for their ability to predict the sampling error of tabular forestry estimates. The recommended GVFs...

Many regional (extensive) forest surveys use clusters of subplots or prism points to reduce survey costs. Two common methods of handling clusters that straddle stand boundaries entail: (1) moving all subplots into a single forest cover type, or (2)"averaging" data across multiple conditions without regard to the boundaries. these methods result in biased...

Uncertainty in the estimation of hydrologic export of solutes has never been fully evaluated at the scale of a small-watershed ecosystem. We used data from the Gomadansan Experimental Forest, Japan, Hubbard Brook Experimental Forest, USA, and Coweeta Hydrologic Laboratory, USA, to evaluate many sources of uncertainty, including the precision and accuracy of...

The demand for timely, consistent, and reliable forest inventory and monitoring information for Wisconsin's state forests has increased significantly. A wide range of publics and partners, including businesses, organizations, and citizens alike are well aware of the benefits of sustainable forestry and are working together to increase knowledge through an annual...

Carbon storage and sequestration by urban trees in the United States was quantified to assess the magnitude and role of urban forests in relation to climate change. Urban tree field data from 28 cities and 6 states were used to determine the average carbon density per unit of tree cover. These data were applied to statewide urban tree cover measurements to determine...

Countries willing to adopt a REDD regime need to establish a national Measurement, Reporting and Verification (MRV) system that provides information on forest carbon stocks and carbon stock changes. Due to the extensive areas covered by forests the information is generally obtained by sample based surveys. Most operational sampling approaches utilize a combination of...

A new taper model was developed based on the switching taper model of Valentine and Gregoire; the most substantial changes were reformulation to incorporate estimated join points and modification of a switching function. Random-effects parameters were included that account for within-tree correlations and allow for customized calibration to each individual tree. The...

There is a growing need within the insular Caribbean for technical assistance in planning forest-monitoring projects and data analysis. This paper gives an overview of software tools developed by the USDA Forest Service?s National Inventory and Monitoring Applications Center and the Remote Sensing Applications Center. We discuss their applicability in the efficient...

A statistical report on the third forest survey of New Jersey (1987). Findings are displayed in 66 tables containing estimates of forest area, numbers of trees, timber volume, tree biomass, and timber products output. Data are presented at two levels: state and county.